As telecommunications networking technologies move from analog to digital transmission, there is a need to maximize usage of the bandwidth available for voice and data transmission.
DS0 (Digital Signal level 0–64 kbps traffic stream) is the smallest increment of manageable bandwidth and is typically used to carry voice information. It is common to transport DS0 traffic within a system in messages having the form of Asynchronous Transfer Mode (ATM) cells. An ATM cell is a fixed-length (53 byte) message comprised of a 5 byte header and 48 byte payload. The DS0 portion of this payload, commonly B-channel and signaling information, is stored in an interleaved manner.
The Synchronous Optical Network (SONET) standard is a set of coordinated ITU, ANSI and Bellcore standards that define a hierarchical set of transmission rates and transmission format.